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A. Ismael

Publications and source records attributed to A. Ismael.

4 recordsLinked to original sources

Resolving $R_{D}$ and $R_{D^*}$ Anomalies in Adjoint SU(5)

We investigate the $R_{D}$ and $R_{D^*}$ anomalies in the context of non-minimal $SU(5)$, where Higgs sector is extended by adjoint 45-dimensional multiplet. One of the light spectrum of this model could be the scalar triplet leptoquark that is contained in this multiplet. We demonstrate that this particular scalar leptoquark mediation of the transition $b \to c \tau \nu$ is capable of simultaneously accounting for both $R_{D}$ and $R_{D^*}$ anomalies. We further emphasize that another Yukawa coupling controls its contribution to $b \to s \ell^+ \ell^-$, ensuring that $R_K$ and $R_{K^*}$ remain consistent with the standard model predictions.

hep-ph

Texture of Two Vanishing Subtraces in Neutrino Mass Matrix and Current Experimental Tests

We present a full phenomenological and analytical study for the neutrino mass matrix characterized by two vanishing $2\times2$ subtraces. We update one past result in light of the recent experimental data. Out of the fifteen possible textures, we find seven cases can accommodate the experimental data instead of eight ones in the past study. We also introduce few symmetry realizations for viable and nonviable textures based on non-abelian ($A_4$ or $S_4$) flavor symmetry within type II seesaw scenario.

hep-ph

Texture of One Equality in Neutrino Mass Matrix

We carry out a phenomenological and analytical study of the texture structures for the Majorana neutrino mass matrix characterized by one single equality between two independent matrix elements, with vanishing non-physical phases whose role in the definition we clarify. We find that fourteen textures are viable in both types of hierarchy, whereas the remaining fifteenth one is viable only in normal hierarchy. We also present symmetry realizations for some patterns by using Abelian flavor symmetries within type-I, type-II and mixed type-(I+II) seesaw scenarios.

hep-ph

Texture of Single Vanishing Subtrace in Neutrino Mass Matrix

We consider a texture for the neutrino mass matrix characterized by one vanishing $2\times2$ subtrace. We analyze phenomenologically and analytically all the six possible patterns, and show that all non-singular ones are able to accommodate the experimental bounds, whereas singular patterns allow only for four inverted-hierarchy type textures. We then present some possible realizations of this texture, within seesaw scenarios, either directly or indirectly by relating it to zero-textures.

hep-ph